Groove inserts are built into rotary cutters or also milling cutters as a replaceable unit in order to be replaced when worn. Groove inserts are extremely small in size such that their secure fastening in the tool holder has to be ensured, also in the case of a lateral feed.
The groove inserts have lateral faces which are exposed in the tool, i.e. the groove inserts are received in a positively locking manner in the receiving means between their top surface and their bottom surface, possibly also their rear surface and are held by means of a clamping force. The opening of the receiving means for replacing the cutting insert is effected by means of a separate lever tool which is to be placed in position laterally and has a bearing continuation which penetrates into an opening in the tool holder and an ejector continuation which penetrates into a rear slot which proceeds from the receiving means. By pivoting the lever tool, the ejector continuation slips along a path and impacts against the bottom surface of the clamping jaw in order to raise said clamping jaw and to spread open the receiving means. As an alternative to this, the ejector continuation can be pressed against the rear surface of the groove insert in order to push said groove insert in the clamped state out of the receiving means.
As an alternative to this, there are solutions where the ejector continuation is able to penetrate into an opening of the clamping jaw and the clamping jaw is able to be moved directly upward.
DE 197 39 855 A1 shows a groove cutting tool having a tool holder where there is a slot on the rear surface proceeding from the receiving means. Said slot has a portion which is greater in cross section and into which the ejector continuation penetrates when inserted, and a connecting portion which tapers toward the receiving means and into which the ejector continuation is pressed when the tool holder is opened. When pivoting the lever tool in the direction of the groove insert, the clamping jaw is pressed upward and the groove insert is able to be pulled out.